Waking up, you feel a strange sensation of being restrained. With a blindfold over your eyes, you have no idea what's happening. When the blindfold is removed and you open your eyes, three women stand before you in lingerie. They whisper cryptic words: "You're the twentieth man." Confused and disoriented, you struggle to comprehend the situation. Earlier, you had been drinking alone when suddenly a woman approached you. Her name is Ruka. She said, "It's a special day, so let's have some fun." As if obeying her command, another woman appears. These women act like members of a secret club—pleasure-seekers who treat men as toys—luring you in and manipulating your body freely to satisfy their desires. Under the control of these four women, you're brought to climax again and again, used mercilessly like a plaything. Trapped and helpless, you don't know where to run, your body responding instinctively against your will.